1. Field
The following description relates to an axle assembly which allows for a more precise measuring of wheel speed by providing a speed sensor on a locking jaw formed at an inner portion of a knuckle of a bearing and a magnetic encoder is provided to the bearing, whereby the speed sensor and the magnetic encoder are closely positioned with each other.
2. Description of Related Art
In general, a mounting structure of a first generation wheel bearing is to press-fit a bearing 1 into a knuckle 2 in an inner side of a vehicle as shown in FIGS. 1A and 1B.
The method of using a tone wheel 3 to measure a wheel rotation speed of a current vehicle has been widely used.
By sensing the movement of the tone wheel 3 mounted on a drive shaft via a wheel speed sensor 5, the wheel rotation speed of the vehicle can be calculated.
On the other hand, in a case that Indirect Tire Pressure Monitoring System (i-TPMS) is provided to a vehicle, using the magnetic encoder for measuring the wheel rotation speed instead of the tone wheel is the current trend.
In the case of using the magnetic encoder instead of using the tone wheel, how the speed sensor is close to the magnetic encoder is the key for accurate measurement.
In the first generation wheel bearing structure, however, there was difficulty in making the magnetic encoder sensor and the speed sensor to be closed with each other.
The case of measuring the wheel speed of a vehicle by using the magnetic encoder with magnetic properties and the speed sensor can measure more accurate and delicate signal than the case of measuring the wheel speed of a vehicle by using the tone wheel and the wheel speed sensor. However, it was difficult to make the speed sensor and the magnetic encoder to be closed with each other in the first generation wheel bearing assembly structure.